lynis_scan · Kali MCP: Risk & Policy

WHAT IT DOES

What lynis_scan does on Kali

AI agents invoke lynis_scan to trigger actions in Kali. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why lynis_scan needs a policy

Lynis is a system security auditing tool that scans the host OS for vulnerabilities, misconfigurations, and security issues. Executing it with arbitrary parameters against target systems constitutes running an external security tool. While it is primarily a read/audit tool, it runs on the host system with elevated privileges and its output could reveal sensitive system information.

From the tool's definition 'Execute lynis with the provided parameters' — runs the Lynis security auditing tool on the host system; server description confirms this is a Kali Linux penetration testing server supporting 'network scanning, web scanning, password attacks'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

lynis_scan Rate-limited

lynis_scan stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "lynis_scan": {
      "limits": [
        {
          "counter": "lynis_scan_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Kali, so you can run agents against it safely.

FAQ

Questions about lynis_scan

What does the lynis_scan tool do? +

Execute lynis with the provided parameters. It is categorised as a Execute tool in the Kali MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on lynis_scan? +

Register the Kali MCP server in PolicyLayer and add a rule for lynis_scan: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Kali. Nothing to install.

What risk level is lynis_scan? +

lynis_scan is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit lynis_scan? +

Yes. Add a rate_limit block to the lynis_scan rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block lynis_scan completely? +

Set action: deny in the PolicyLayer policy for lynis_scan. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides lynis_scan? +

lynis_scan is provided by the Kali MCP server (pentestt00ls/kali-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.